In the prior art, various methods and devices are used for the determination of concentration of ammonia in chemical and biochemical compounds. However, there is no previously known procedure or apparatus that enables the ammonia content of a liquid to be quickly determined without complex analyses.
Dall'Olio et al, Akad. Sci., Ser.C 267 (1968) 8, p.433-435 disclosed the possibility of electrochemical polymerisation of pyrrole. Diaz et al, J.C.S. Chem. Comm. (1979) p.635-636 disclosed the conditions that allow electrochemical polymerisation of pyrrole on platinum, resulting in a durable electrode film with enhanced electrical conductivity and strong adherence. Bull et al, J. Electrochem. Soc., 129 (1982), showed that a polypyrrole film deposited on platinum exhibits electron transfer reactions in solutions. Kanazawa et al, J.C.S.Chem. Comm. (1979), p.855-856, disclosed that exposing a polypyrrole film to ammonia reduces the conductivity of the film. Miasik et al, Conducting Polymers, Alcacer (ed.), D. Reidel Publishing Company (1987), p. 189-197, disclosed that a thin polypyrrole film formed by electropolymerization from an aqueous solution of pyrrole monomer and LiBF4 can be used as a chemiresistor sensitive to ammonia, i.e. as a resistor whose resistance value depends on the chemical composition of the substance which surrounds it and is in contact with it, in this case ammonia. The film was able to detect an ammonia content of 0.1% in air. U.S. Pat. No. 5,089,294 disclosed that a chemiresistor based on polypyrrole film can be used for detecting the concentration of ammonia in atmospheric air by measuring the change in the resistance value.